The present invention relates to a seat belt system installed in a vehicle, such as automobile, for restraining and protecting an occupant by means of a seat belt and, more particularly, to a seat belt system provided with a belt controller for controlling the belt tension on the seat belt to correspond to the driving situation of the vehicle.
A seat belt system installed in a vehicle, such as automobile, comprises a seat belt retractor. In general, the seat belt retractor always biases the seat belt in a belt winding direction by means of a spiral spring so as to fit the seat belt on an occupant""s body and to wind up the seat belt to store the seat belt therein when the seat belt is not used. Further, the seat belt retractor stops the withdrawal of the seat belt in case of emergency, such as vehicle collision, thereby preventing the forward movement of the occupant due to inertia.
In the conventional seat belt system, the seat belt is always biased in the belt winding direction without controlling the belt tension. Therefore, the force required for withdrawing the seat belt becomes too large to allow light handling of the seat belt. In addition, since the occupant is tightened hard by the force of the spring when the occupant wears the seat belt, the occupant feels oppression.
Therefore, it has been proposed in Japanese Unexamined Patent Publication No. H09-132113 to control the belt tension to improve comfortableness by reducing the force required for withdrawing the seat belt for wearing the seat belt and by setting the tension on the seat belt small in a normal wearing state and, and in addition, to improve the safety of the occupant by setting the tension large when it is determined by collision predictive means that there is a high possibility that the vehicle may come into collision.
According to this seat belt system, the belt tension can be controlled corresponding to the driving situation of the vehicle, whereby effective protection of the occupant can be expected.
In the seat belt system of the aforementioned publication, the control of the belt tension is applied only when the occupant withdraws the seat belt, when the occupant puts on the seat belt, and when it is determined by the collision predictive means that there is a high possibility that the vehicle may come into collision. However, the control of the belt tension is required not only the aforementioned situations but also other situations while the occupant is getting on the vehicle, the vehicle runs and the like. Therefore, it is hard to say that the conventional seat belt system can completely assure the safety and the compatibility of the occupant.
The present invention has been made under the aforementioned circumstances, and an object of the invention is to provide a seat belt system which can more effectively and completely assure the safety and comfortableness of the occupant.
To solve the above problems, the invention in a first aspect resides in a seat belt system having at least a tension controller for controlling the belt tension on a seat belt, which includes occupant""s state detecting means for detecting the state of an occupant in wearing the seat belt and outputting a detected signal; and a central processing unit (CPU) for controlling the tension controller based on the detected signal from the occupant""s state detecting means.
In addition, in a second aspect of the invention, the state of the occupant is indicated by at least one of parameters including the heart pulse rate, the blood pressure, the body temperature, and the bioelectric potential of the occupant. The CPU controls the tension controller in such a manner that the belt tension is increased with increasing the value of one or more of the parameters.
Further, in a third aspect of the invention, the occupant wearing the seat belt is a driver of the vehicle and that the state of the occupant is indicated by the action for operating the vehicle.
Further, in a fourth aspect of the invention, the action for operating the vehicle is selected from at least one of parameters including a speed for releasing an accelerator pedal, a speed for pedaling a brake pedal, a force exerted on the brake pedal, and steering angle. The CPU controls the tension controller in such a manner that the belt tension is increased with increasing the value of one or more of the parameters.
Further, the invention in a fifth aspect resides in a seat belt system having at least a tension controller for controlling the belt tension on a seat belt in which several predetermined modes having different belt tensions are set for the belt tension control, which includes demonstration means for outputting a simulation signal for one of the modes when the one mode is selected by the occupant wearing the seat belt, and a central processing unit (CPU) for controlling the tension controller, based on the simulation signal from the demonstration means, to set the belt tension corresponding to the mode indicated by the simulation signal.
Further, in the sixth aspect of the invention, the modes set for the tension control include at least a comfort mode in which the occupant does not feel pressure on his or her body when the occupant wears the seat belt, a warning mode operated in a condition such that an object comes closer but the collision with the object can be avoided, and a pre-rewinding mode operated in a condition such that an object comes closer and the collision with the object can not be avoided. The CPU controls the tension controller so as to set the belt tension corresponding to one of the modes.
Further, a seventh aspect of the invention resides in a seat belt system having at least a tension controller for controlling a belt tension on a seat belt, which comprises notifying means for outputting a notifying signal for notifying the occupant of various information with different belt tensions, and a central processing unit (CPU) for controlling the tension controller based on the notifying signal from the notifying means.
Further, in an eighth aspect of the invention, the various information comprises at least one information about a corner running, a roughness of a road surface, raindrops, an engine speed, a vehicle speed, lightning of headlamps, a rapid acceleration, a lighting of each indicator, actuation of an anti-locking brake control system, actuation of traction control system, arrival at a destination by a navigation system, a sporty mode set in a suspension control system, and a sporty mode set in a transmission system for a driving range. When it is determined based on the information about the corner running that the vehicle runs on a corner, when it is determined based on the information about the roughness on the road surface that the vehicle runs on a bumpy road, when it is determined based on the information about the raindrops that the vehicle runs in the rain, when it is determined based on the information about the engine speed that the engine runs at a speed higher than a reference engine speed, when it is determined based on the information about the vehicle speed that the vehicle runs at a speed higher than a reference vehicle speed, when it is determined based on the information about the lighting of the headlamps that the headlamps are turned on, when it is determined based on the information about the rapid acceleration that the vehicle accelerates rapidly, when it is determined based on the information about the lighting of the indicators that one of the indicators is turned on, when it is determined based on the information about the actuation of the anti-locking brake control system that the anti-licking base control system is actuated, when it is determined based on the information about the actuation of the traction control system that the traction control system is actuated, when it is determined based on the information about the arrival at a destination by the navigation system that the vehicle arrives at the destination, when it is determined based on the information about the sporty mode setting in the suspension control system that the suspension control system is set in the sporty mode, or when it is determined based on the information about the sporty mode setting in the transmission system for the driving range that the transmission control system is set in the sporty mode, the CPU controls the tension controller to increase the belt tension.
Further, the invention in a ninth aspect resides in a seat belt system having at least a tension controller for controlling a belt tension on a seat belt in which several predetermined modes having different belt tensions are set for the belt tension control, which comprises control condition setting means for outputting a setting signal for setting each mode; and a central processing unit (CPU) for controlling the tension controller, based on the setting signal from the control condition setting means, to set a condition for each mode.
Further, in a tenth aspect of the invention, the conditions for the modes comprise values to be set for each mode for the belt tension control, conditions to be satisfied for setting each mode for the belt tension control, and a sound to be emitted when each mode is set for the belt tension control.
Further, in an eleventh aspect of the invention, at least two of the first, fifth, seventh and ninth aspects may be combined.
Further, in a twelfth aspect of the invention, the system further comprises at least one of collision predictive means for detecting an object around the vehicle and outputting a signal to the CPU and rolling-over detecting means for detecting the rolling over of the vehicle body and outputting a signal to the CPU. The CPU controls the tension controller based on the output signal.
In the seat belt system structured as mentioned above according to the present invention, the belt tension is controlled corresponding to the state of an occupant wearing a seat belt, thereby effectively protecting the occupant. In addition, by using simulation signals, the occupant can feel the belt tension in each mode. This ensures that the occupant can securely know which tension control mode is set at present. By the belt tension, the occupant securely and easily knows the condition of the vehicle, the running condition of the vehicle, or the setting conditions of the respective control systems installed in the vehicles. In addition, since the conditions to be satisfied for the respective tension control modes can be set by the occupant wearing the seat belt, the occupant can set the belt tension to his or her preference.
Therefore, the seat belt system of the present invention can effectively exhibit enough safety and comfortableness for the occupant.